Method of froducing alkali-metal sulphydrates



Patented July 19, 1927.

UNITED STATES PATENT OFFICE.

mas! locum run, or rams, rmca, asa'mnoa 'ro rumza aarnrrcur. snx

001mm AMERICA, A CORPORATION 01' .DILAWARI.

humor or nonucnre Lanai-urn. sunrmmm I. Drawing. Application fled January 88, m4, Berta! Io. 08.34am in Great Britain January 81, I

The invention relates to the improvements in the production of alkali-metal sulph drates. I

' om unds of sulphur with alkali metal I or alka ine earth metal, such for'example. as Th hydrosulphides are generally produced by saturating alkali metal or alkaline earth hydroxides or sulphides with hydrogen sulhide in aqueous solution. Thiosulphates,

or instance, are produced by boiling the solution of an alkali metal or alkali earth metal sul hite with sulphur or by oxidizin alkal i metal or alkali earth metal su phides, or finally b the .action of sull5 phur dioxide on sulp ides. Alkali metal or alkali iearth metal sulphides are produced by reducing the sulphates with.

, carbon at high temperatures. Generally these processes are very cumbersome and I) more or less expensive and moreover the use of sulphur with dioxide and sulphuretted hydrogen on an industrial scale is unpleasant. The present invention aims at overcoming these drawbacks and provides a sim- I ple process for the production-of compounds of sulphur and alkali metal or alkaline earth metals, which enables to roduce hydrosulphides, thiosulphates, sulphides, or'mixtures thereof, at will in one operation.

p I have found that if a mixture of alkali metal sulphate, and preferably heavyhydrocarbon oils (of the kind specified below) is heated with or without finely divided sul-I phur to dull red heat in a closed vessel, in

absence of air, but provided with an outlet for the escaping reduction ga'ses, -alkali metal hydrosulphide is mainly" produced. The

proportion of sulphur and hydrocarbon oils use mafy vary within wide limits. Inthe 40 course 0 the reduction-of the alkali'metal .Bu lphatesi complex chemical reaction takes place an as intermediatesta'ge in the for mation of alkali metal hydrosulphides, alkali ,metal' sulphites and a kali metal thiosulphates are formed. The formation of these.

compounds occurs already atlow dull red "heat and if desired the reactioncan be stopped at that stage by cooling the mass down, and the alkali, metal thiosulphate which is mainly formed eliminated by lixiviation together with fractional'crystallization of the aqueous extract thus obtained in the well known manner. This intermediate reaction also, occurs atlittle higher temperalower' tem degree, but these are also converted finally into alkali metal hydrosulphide. 1

The heavy hydrocarbon oils act as powerful reducing agents and accomplish the reduction of the alkali metal sulphates at ratures thanthose hitherto practiced by nown methods.' The heavy hydrocarbon oils and sulphur act on the alkali metal sulphates 'at the above named heats and produce complex chemicalreactions and as a final react-ion "product alkali metal hydrosulphides are produced in the main and small quantities of alkali carbonates. The

hydrocarbon oils, paraflin oils, petroleum and others, undergo decomposition and cracking; and lighter hydrocarbons formed can be distilled off. The formation of some sulphuretted hydrogen is also observed and this can be drawn off and is suitably absorbed.

The same reaction can'be applied to alkali metal bisul hates or "to mtrecake; these products yie d wh' n reduced with heavy hydrocarbon oils and @111 bur at dull red heat,

alkali metal hydrosul ides.

Alkali metal sulp lites, likewise behave similarly as 'alkali metal sulphates and yield under the above conditionsalso alkali metal hydrosulphides. The sulphur] used in the i above examples may be partially or completely replaced by finely divided 'ground lI'OIl pyrites, or other sulphides of heavy metals, such as co per and lead. In case of reduction of alkal metal sulphates or alkali metal 'sulphites, it can be replaced also b alkali metal polysulphides. These ield su "hur and themselves are converts into alalimetal hydrosulphides during the reduction. a

Alkali metal thiosulphates can be reduced directly with heav hydrocarbon oils under the above heat con itions, or sulphur may be added oriron yrites with formation 0 alkali metal hyd i osulphides.

The reduction of alkali metal sulphates or sulphites or-alkali meta-l bisulphates or nitrecake can also be carried out wlth heavy hydrocarbon'oils, without the addition 'of sulphates,

sulphur or materials producing such; the

-final reduction products'contalmng, however, lar r proportions of alkali carbonate besides t e alkali metal hydrosulphide, than otherwise would be the case.

When insuflicient hydrocarbons are present during the reduction of the alkali metal sulphites or alkali metal thiosulphates, alkalimetal sulphides are formed, in reference to alkali metal h drosulphides.

aline earth metal sulp ates, such as calcium or barium sulphates are reduced b heavy hydrocarbon oils at dull red heat wit 1 great ease, and almost white alkaline earth metal sulphides are being formed. By the ordinary methods'of reduction of these sulphates with carbon or carbon bearing materials, much higher temperatures are required and 9001200 C. are generally maintained; and the products of reduction obtained are of far less purity than is the case above. This reduction of the sulphates of the alkaline earth metals, can be carried out with heavy hydrocarbon oils with or without the addition of sulphur. The formation of alkaline earth metal thiosulphates only occurs in a small de ree and a few percent only were observed to e intermediately formed. The formation of alkaline earth metal hydrosulphide likewise only occurs in 'aminor de ree and chiefly alkaline earth metal sulphldes are being produced. In any and all of the stated examples, the reduction can be carried out at dull red heat at ordinary or increased pressure and in absence or presence of cata lytlcal substances such as iron or copper or nickel or their sulphides.

The sulphur and heavy hydrocarbon oils or both may be added gradually during the heating of the alkali metal sulphates or sulphites or thiosulphates under reduction,

either as such or in form of spra s or heavy tar oils from ordinary gas wor organic su vapours or the sulphur ma be suspen ed or dissolved in the hydrocar on oils previous to addition. The reduction may be carried out in vessels of iron, nickel or nickel steel and other metals or alloys resisting. temperature and chemical action or ingraphite or alkali resisting crucibles.

As hydrocarbons maybe used, li ht arlixd co e ovens, producer gas plants, neutral wood tar, shale o l, heavy hydrocarbons such as natural occurring oils, higher boiling araflin oils, crude parafiin oils, troleum oi s, crude petroleum oil containing more or less sulphur,

residues of distillation of heavy hydrocarbon oils, or other sources of hydrocar on oils in general. These oils must not be too volatile, their boiling point being approximately 200-300 C. 'or over, they ,contain a great range of h drocarbon compounds and other ances. These hydrocarbons of various origins may be used alone or mixed together, furthermore, other hydrogenated atmosphere, this being generally the reduction gases formedabsorbed-by caustic soda or or thiosul hates or vnitrecake or alkalineearth meta sul hates, can also be carried out with heavy h rocarbons and sulphur in the presence of reducin gases such as hydrogen or water gas or pro men as, provided these do not contain an marked quantities of carbondioxide gas; t e operation can be effected at ordinary or increased'pressure or in the presence of catalytical agents such as iron,

copper or nickel or their sulphides. Other lighter hydrocarbons in general and sulphur also effect the reduction of alkali metal sulphates or sulphites of bisulphates or thiosulphates or alkali. earth metal sulphates with similar results as stated, on account oi their volatilizing, their use is, however, less advantageous.

Having now described the general idea of the invention the followin exam le will illustrate in what manner t e sai invention is carried out."

Example 1.

Production of alkali metal hydroaulphide.-An intimate mixture of one part of alkali. metal sulplhate, with 0.25 part of finely divided sulp ur and 0.5 part of heavy neutral tar oiheavy crude petroleum oil, is heated to d heat .in a closed iron vessel in absence of air. The apparatus is p'rovided with a stirring gear and with an outlet for the escape of gases formed during the reaction and heated externally by anyosource of heat. An evolution of hydrocar n vapours, carbon monoxide and some sulphuretted hydrogen takes place and the reduction of the alkali metal from gas works, or

an vapours of hydrocarbons are carried away by an exhaust pi ullred' III are condensed-and can be used again, w ereas hydrogen sul- 'phide is absorbed by well known means.

' After heating'the mass while stirring for 30-40 minutes, the evolution of the hydrocarbon vapours and slows down and the reduction is comp etc. the reaction can be ascertained b small samples with a dipper an them by titration. the mass must always taking testing During the operation be kept in a reducing b th d h h y e vapours an gases given 0 t roug heating from the tar oils or heavy petroleum The progress of 1 vessel to, which access of tains besides alkali oils. When the reductionis'completed the mass represents a semi-molten mass to molten mass, which may be cooled down in a reducing or inert atmosphere, or poured into a air is prevented. The reaction mass, when cooled down represents a very orous mass, which is very hyg'roscopic an undergoes slow decom ition, when exposed to air sulphurette h (1 en being evolved. lt re resents tile cru e alkali metal sulphydrate ormed.

In the above example, the whole ofthe quantities of tar oil or heavy petroleum oil, need not be mixed from the outset with the alkali metdl sulphate; one ma add only half ontwo thirds o them-and ad the remainder through a suitable opening in the reaction vessel, during the further heating of the y. mass. The quantities of sulphur and tar oils or heavy petroleum oils ma' be further increased than indicated, which somewhat favors the formation of alkali metal hydro.- sul hide.

he crude reaction mass obtained, conmetal hydrosulphide,

. small quantities of alkali carbonate, alkali metal polysulphi chiefly carbon. The

' the greater part 0 alkali metal hite, occasionally alkali es and insolublev matter, mass is readily soluble in water, ,the solution has a strong alkaline metal thiosulphate, traces of sulphate .and sul reaction. By adding a small quantity of' the alkali metal sulphy-' drate is brought into solution first, leaving cold water only,

f the other compounds unsolution can be decanted if desired by evaporation alternative .way consists in dissolved. The and concentrated in-vacuum. An

heating the aqueousextract with a small quantity of slacked lime or calcium chloride solution, thus eliminatin these mentioned impurities, and concentrating. the clear. solution by evaporation in.vacuum.

, In the above described. example one can also admit hydrogen .or water as, or producer gases free from carbon ioxide gas, during the reduction,

which assist theres'ulphates. .The adquantities of catalytical agents such as 'finely divided iron or. nickel, or cop er or their .sulphides 'can also be effect without changing the result of the reaction. The reduction can also out at increased pressure. i seesaw d. Produetioa' of alkali mm tlu'oml phate.-'The mixture of alkali metal sulhate andsulphur and heavytaroils, or

, eavy petroleum oils is heated in a closed vessel as described above to fsliglhtly lower temperatures, i. e., begin at .du red heat. Almost the'totality of the alkali sulphate is transformed into alkali metal thiosulphate, containing varying proportions be carried of alkali high, the reduction can be sto ed before.

any substantial "amount of the ast named products are being formed. The mass is thereupon cooled and the alkali metal thiosulphate is dissolved out with water and after concentration or stallized' out.

6. Production f metal hydroa'ulphz'de from alkali metal thiosulphates.-If the reduction is carried further 2, by heating the mass longer or to big or temperatures and by adding further quantities of heavyhydrocarbons, the alkali metal thiosulphate formed is transformed into alkali metal hydrosulphide. Thesame result can be obtained'by subjecting dry alkali metal thiosulphate directly to the reduction of heavy tar or petroleumoils at dull red heath If the reductionis carried out with the addition of sulphur, alkali metal hydrosul hide is also produced and sulphuretted hy rogen is evolved. I.

a a Example 3.

Production of alkali metal hydromllpha'dee from "alkali metal eulqrkites.Alkali metal sulphites can likewise be reduced by heavy tar oils or heavy petroleum oils and sul but, with formation of alkali hydrosul ides. The same conditions are maintained as in Example 1 and the alkali metal sulphites behave in the 'same during the reduction.

* Example 4.

a. Production of alkali metal sulphides.- When the proportion of heavy hydrocarbons, or heavy petroleum oil .in the above three exam les,-1s insuflicient for the production of alkal m tal hydrosulphides, alkaliv metal sulphides are for instance, when the proportionof hydrocarbons entering reaction'is only 0.05-0.10 part to every part of alkali. metal sulphate or sulphite or thiosulphate, .the formatlon of manner as their sulphates in Exam le produced, 1n preference. Thus,

alkali metal sulphides occurs at dull red heat and m presence as stated of sulphur.

b. Prodwtz'on of alkaline earth metal sulphides.The reduction of alkaline earth metal sulphates, such as calcium or barium sulphate,

ough higher temperatures may be used and furthermore to their respective sulphides, with heavyhydrocarbons or heavy petroleum oils yields w en heated ratures apmation of sulphides, the sulphur bein known manner.

alkali earth metal sulphates is carried with ple'x chemical reaction taking the reduction proceeds much more rapidly and completely. Barium sulphate can be reduced m a similar way and'it reduces easily and quantitatively to an almost white barium sulphide; the ordinary rocess when reduction takes place with car on, yields a dark colored product and in lower yields. Example: 25- parts of finely ground barium sulphate are mixed intimately with 5-10 parts of heavy paraflin oil and heated in a closed vessel, while being stirred, to dull red heat. The heating is continued for 25-30 minutes, an evolution of hydrocarbon vapours takes place to ether with carbon monoxide and some sulphuretted hydrogen. The

reduction of the sulphate proceeds rapidlyv and is generally finished in the time stated and when the evolution of gases is finished. The reaction mass is cooled in a reducing atmosphere of hydrocarbon vapours and represents an almost white powder, consisting of almost pure barium sulphide. It can be recrystallized from hot water in the well If the reduction of the heavy hydrocarbons and with the addition of sulphur, the result is the same, the fortilized'as such and as sulphuretted hy rogen during the reduction.

Example 5.

with hydrocarbons. When these carbons or heavy hydrocarbon oils and without sulphur or metallic sulphides, to dull red heat in a constantly reducing atmosphere, as described in Exam le. 1, the reaction product contains besides a ali metal hydrosulphide,

alkali carbonate and this in a larger proportion than-if sulphur were used. The complace .also seems to differ inasmuch as onl small quantities of alkali metal thiosulpliateare produced as intermediate products or none at all and hydrogen sulphide is not formed.

Example 6'. reduction of alkali metal hgjdromlphides from alkali metal bisulphatee or nitrecake.-'-

,When alkali metal bisulphates or a product same, such as nitrecake are reduced wit heavy tar-oils,-or-hea paraflin oils, or crude petroleum oils, direct y or with the addition of sulphur at dull red heat, alkali metalhydrosulphidw are obtained. The following example will show how the reaction is carried out. i

100- parts of nitrecake, as obtained norcontaining1 ring gear and with an out volaatter named compounds are heated with hydrof mally in the manufacture of nitric containing varying amounts of bisulphate, are mixed with 20 parts of finely divided sulphur and 45 parts of heavy troleum oil. -The mass is heated todull heat in a closed iron vessel, rovided with stiret for the escape of the gaseous products from the reduction mass. The hydrocarbon soon undergoes a process of cracking and decomposition, the mass begins to foam and assumes quite a liquid 1 state. An evolution of hydrocarbon vapours take place and of carbon monoxide and of sulphuretted hydrogen, the latter of which can be suitabl absorbed. When the foaming has subsi ed, the mass assumes a clear liquid state. At this stage, while stirring well, a-further quantit of 5 arts of sulphur is admitted to the me t gra uall The re-v duction is generally completed a ter heating the mass for 35-45 minutes and this can be ascertained b taking a sample. and testing it in the well known way for sulphates. The mass is then cooled down in areducing atmosphere of hydrocarbon vapors or an inert gas. It represents a orous grey mass easily soluble in water, wit

Example 7'.

Production of alkali metal h dromlplu'da rom alkali metal, polyaulpzuia' metal diighphides, or polysul hide, are, when hea with has neutra tar 0 or heavy paraflin oils cru e or refined to acid, .a

the exception of insoluble matters, consistin chiefly of carbon.

red heat, converted into alkali sulpliydrates.

This conversion to sulplhggrates also place when alkali sul i is heated with sulphur and heavy hy rocarbons. These operations may also be carried out in presume of hydrogen or gases containing such. A1- kaline earth metal sul hide suc as calcium sulphide and polysulp ides heated with In]- phur and heavy hy rocarbons to low dull red heat yield calcium sulphydrate (in small proportion). v

vThe results obtained in the above described reaction are entirely union-seen, in-

asmuch as allthe methods of reduction of alkali metal sulphates with ol'fillc compounds (chiefly carbon) hitherto own, describe the production of alkali metal suL phide only. 1

It is evident that numerous modifications and alterations ma be made, thus the whole range of saturat and unsaturated carbons and sulphur can be used in the de-;

takes no alkaline earth metal sulphides, can be pro- I duced at will in one simple operation and scribed processes without altering the spirit of the invention.

I have established that alkali metal hydrosulphides, alkali metal thiosulphates, al-- kali metal sulphides or mixtures thereof, or

that the hydrocarbons not only act as powerful reducin'gla ents, but when producing aly rosulphides, they supply the. hydrogen required for the formation of these compounds by way of complex chemical reactions.

Having now described my invention, what I claim as new and desire to secure by Lettars Patent,is: I a

1. The method of producing alkali metal sulphydrates which consists in heating on alkali metal sulpho compound with h drocarbon oils and suphur in quantity sug- .cient to efiect the reduction.

2. The method of hydrates which consists in heating sodium isulphate with hydrocarbon oil and sulphur in quantity sufiicient to efiect the reduction.

3. The production of alkali metal sul hydrates by reducin alkali metal -sulp oxy compounds with eav hydrocarbons in presence of sulphur at ullred heat and un. 30 der exclusion of air. ERNEST EUGENE N AEF.

roducing sodium sul- 

